Question 1

As part of the iguana risk assessment experiment described in the previous problem, investigators replicated the experiment with one difference--the investigators approached the iguanas at a tangent, passing by the iguana with a closest distance being 2 meters. Summary statistics for the approach distances for the two treatments, Eye Contact and No Eye Contact, are given in the table below:  An initial analysis of the data revealed that it was reasonable to assume the population approach distances at first run were both approximately normal.
a)Construct a 95% confidence interval for the difference in approach distances for the eye contact and no eye contact treatments.
b)Do the data indicate that for a tangential approach, the population means differ? Justify your answer statistically.

Accepted Answer

The answer of As part of the iguana risk assessment...

Question 2

A common memory task is the classification of objects into categories. For example, a table is a piece of furniture; a dog is an animal, etc. This classification capability was used in a recent study of divided attention. Elderly adults were randomly selected from those answering a newspaper advertisement, and randomly assigned to two conditions: divided attention and no divided attention. Subjects in the "divided attention" group were told to memorize a list of 36 words while simultaneously listening to a tape recorder; subjects in a control group were told to memorize a list of 36 words and did not listen to a tape recorder. Subjects were then asked to classify the 36 words into 6 categories. (There were 6 words in each category.) The distributions of the correct number of recalled words / category were approximately normal in each of the groups, and a summary of the data for the words/category recalled are presented below:  ​
a)Is there evidence that the memory performance differs in the two groups? Test the appropriate hypothesis using α = .05.
b)One possible implication of this study is that high school students should not be dividing their attention by listening to music while studying. What results, if any, of this study would support the contention that students should not be dividing their attention?

Accepted Answer

The answer of A common memory task is the classification...

Question 3

When testing hypotheses involving treatment effects in an experiment, the conclusions of any inference test should be worded in terms of what quantities?

Accepted Answer

The answer of When testing hypotheses involving treatment effects in...

Question 4

Suppose a researcher is testing a new diet drug. She would like to determine if the drug helps to significantly increase weight loss versus a placebo. She randomly assigns 40 participants to the treatment group and 35 to the placebo group. After 4 weeks on identical diets, the mean weights loss (in pounds) for each group is computed. Results of the study are as follows:
Treatment Group
Placebo Group
n = 40
n = 35 
 = 5.6 
 = 1.6
s = 2.85
s = 1.47
Create a 95% confidence interval for the difference of treatment effects.

Accepted Answer

The answer of Suppose a researcher is testing a new...

Question 5

When creating a confidence interval involving treatment proportions in an experiment, the interpretation of the confidence interval estimate should be worded in terms of what quantities?

Accepted Answer

The answer of When creating a confidence interval involving treatment...

Question 6

Suppose a researcher is testing a new diet drug. She would like to determine if the drug helps to significantly increase weight loss versus a placebo. She randomly assigns 40 participants to the treatment group and 35 to the placebo group. After 4 weeks on identical diets, the mean weights loss (in pounds) for each group is computed. Results of the study are as follows:
Treatment Group
Placebo Group
n = 40
n = 35  = 5.6  = 1.6
s = 2.85
s = 1.47
Perform a hypothesis test to draw a conclusion from this study. Show all your work.

Accepted Answer

The answer of Suppose a researcher is testing a new...

Quiz 13: Asking and Answering Questions About the Difference Between Two Means

When testing hypotheses involving treatment effects in an experiment, the conclusions of any inference test should be worded in terms of what quantities?

When creating a confidence interval involving treatment proportions in an experiment, the interpretation of the confidence interval estimate should be worded in terms of what quantities?